Technical Field
[0001] The present disclosure relates to an edging method and an edging device.
Background Art
[0002] In a rough rolling procedure of a hot rolling process, sometimes bending deformation,
referred to as camber, occurs in a steel strip. One cause of camber of the steel strip
during the rough rolling procedure is temperature variation that arises inside a heating
furnace across the width direction of a slab.
[0003] Japanese Patent Application Laid-Open (
JP-A) No. H03-254301 describes technology in which, in cases in which a temperature variation is present
across the width direction of a slab, a pair of dies are moved relatively in a conveyance
line direction, and a pair of side guides upstream on a conveyance line are moved
aligned with a conveyance line center of an edging device, thereby suppressing camber.
[0004] Japanese Utility Model Application Laid-Open (
JP-U) No. S62-96943 describes technology in which a guide device with guide rolls is provided at a slab
entry side or a slab exit side of a sizing press. Camber is suppressed by restraining
the slab such that a center position in the width direction of the slab and a center
position in the width direction of the sizing press are aligned with each other.
[0005] Japanese Patent Application Laid-Open (
JP-A) No. S61-222602 describes a camber control method for full-length width reduction press of a hot
slab, the method includes the step of: when pressing down the hot slab continuously
with a press, measuring the camber of the hot slab during pressing by means of a camber
detector attached to an outlet side of the press, rotating a pinch roll on the outlet
side of the press based on the measured value and inclining upper and lower rollers
axial centers of the pinch roll in the horizontal plane with respect to the slab delivery
direction, and correcting the hot slab camber generated during the press.
[0006] Japanese Patent Application Laid-Open (
JP-A) No. 2001-179301 describes a method for centering a hot slab in an edging device, wherein a position
and angle of an inlet side guide and/or an outlet side guide are adjusted based on
information of the hot slab obtained at at least one of prior to edging or after edging
adjustment so as to align a center line of the hot slab with a true center line of
the edging device.
SUMMARY OF INVENTION
Technical Problem
[0007] In the technology described in
JP-A No. H03-254301, although camber of the slab is suppressed at the exit side of the edging device,
a slab thickness variation (asymmetry in the slab thickness distribution) arises in
both lateral face portions in a width direction in the slab cross-section, so as to
form a dog-bone profile.
[0008] In the method described in
JP-U No. S62-96943, camber of the slab on the exit side of the press is not suppressed in cases in which
temperature variation arises in the slab width direction. Moreover, a slab thickness
variation (asymmetry in the slab thickness distribution) arises in both lateral face
portions in a width direction in the slab cross-section.
[0009] Even if camber does not occur after pressing, if a slab thickness variation (asymmetry
in the slab thickness distribution) is present between the both lateral face portions
in a width direction in the slab cross-section, during later rolling by horizontal
rolls, the slab thickness stretches further in the length direction at the side with
the thicker slab thickness than at the side with the thinner slab thickness. This
results in the occurrence of camber in the slab.
[0010] In consideration of the above circumstances, an object of the present disclosure
is to suppress the occurrence of camber in a slab during an edging process of the
slab during a rough rolling procedure of a hot rolling process.
Solution to Problem
[0011] An edging method of the present disclosure includes the steps according to claim
1.
[0012] An edging device of the present disclosure includes the features according to claim
4.
Advantageous Effects of Invention
[0013] The present disclosure enables camber to be suppressed from occurring in a slab that
has undergone an edging process of the slab during a rough rolling procedure of a
hot rolling process.
BRIEF DESCRIPTION OF DRAWINGS
[0014]
Fig. 1 is a schematic configuration diagram of a rough rolling procedure of a hot
rolling process employing an edging method and an edging device of a first exemplary
embodiment.
Fig. 2 is a plan view schematically illustrating an edging device of the first exemplary
embodiment.
Fig. 3 is a plan view illustrating a state prior to edging of a slab in an edging
device of the first exemplary embodiment.
Fig. 4 is a plan view illustrating a state following on from Fig. 3, in which a trailing
end side of the slab sandwiched between a pair of plate members is moved in a width
direction of the conveyance line to apply an incident angle to the slab, while edging
a leading end side of the slab.
Fig. 5 is a plan view illustrating a state in which the trailing end side of the slab
has moved further in the width direction of the conveyance line than in the state
illustrated in Fig. 4, thereby increasing the incident angle.
Fig. 6 is a plan view illustrating a state in which the trailing end side of the slab
has moved even further in the width direction of the conveyance line than in the state
illustrated in Fig. 5, thereby increasing the incident angle.
Fig. 7 is a plan view illustrating a state in which the trailing end side of the slab
is being edged.
Fig. 8 is a plan view illustrating a state in which the edged slab has moved downstream
of an edging member along the conveyance line.
Fig. 9 is a plan view illustrating a state in which a slab is being edged using an
edging method of Comparative Example 1.
Fig. 10 is a plan view illustrating a state in which a slab is being edged using an
edging method of Comparative Example 2.
Fig. 11 is a schematic diagram illustrating a cross-section profile of a slab prior
to edging, and a temperature distribution across the slab width direction.
Fig. 12 is a schematic diagram illustrating a cross-section profile of a slab after
edging.
Fig. 13 is a plan view illustrating a state prior to edging of a slab in an edging
device of a second exemplary embodiment.
Fig. 14 is a cross-section taken along line L14-L14 of Fig. 13, and illustrates means
employed to find a slab thickness variation across a slab width direction prior to
edging.
Fig. 15 illustrates a first modified example of an edging device of the second exemplary
embodiment, and is a cross-section (a cross-section corresponding to Fig. 14) illustrating
means employed to find a slab thickness variation across a slab width direction prior
to edging.
Fig. 16 illustrates a second modified example of an edging device of the second exemplary
embodiment, and is a cross-section (a cross-section corresponding to Fig. 14) illustrating
means employed to find a slab thickness variation across a slab width direction prior
to edging.
Fig. 17 is a schematic diagram (a schematic diagram corresponding to Fig. 12) illustrating
a cross-section profile of a slab after edging.
Fig. 18 is a plan view illustrating a state prior to edging of a slab in an edging
device of a third exemplary embodiment.
Fig. 19 is a schematic diagram (a schematic diagram corresponding to Fig. 12) illustrating
a cross-section profile of a slab after edging.
Fig. 20 is a plan view schematically illustrating an edging device of a fourth exemplary
embodiment.
Fig. 21 is a plan view illustrating a state prior to edging of a slab in an edging
device of the fourth exemplary embodiment.
Fig. 22 is a plan view illustrating a state following on from Fig. 21, in which a
trailing end side of the slab sandwiched between a pair of plate members is moved
in a width direction of the conveyance line to apply an incident angle to the slab,
while edging a leading end side of the slab.
Fig. 23 is a plan view illustrating a state in which the trailing end side of the
slab has moved further in the width direction of the conveyance line than in the state
illustrated in Fig. 22, thereby increasing the incident angle.
Fig. 24 is a plan view illustrating a state in which the trailing end side of the
slab has moved even further in the width direction of the conveyance line than in
the state illustrated in Fig. 23, thereby increasing the incident angle.
Fig. 25 is a plan view illustrating a state in which the trailing end side of the
slab is being edged.
Fig. 26 is a plan view illustrating a state in which the edged slab has moved downstream
of an edging member along the conveyance line.
Fig. 27 is a plan view schematically illustrating an edging device of a fifth exemplary
embodiment.
Fig. 28 is a cross-section taken along line L28-L28 of Fig. 27, and illustrates means
employed to find a slab thickness variation across a slab width direction after edging.
Fig. 29 illustrates a first modified example of an edging device of the fifth exemplary
embodiment, and is a cross-section (a cross-section corresponding to Fig. 28) illustrating
means employed to find a slab thickness variation across a slab width direction after
edging.
Fig. 30 illustrates a second modified example of an edging device of the fifth exemplary
embodiment, and is a cross-section (a cross-section corresponding to Fig. 28) illustrating
means employed to find a slab thickness variation across a slab width direction after
edging.
Fig. 31 is a plan view schematically illustrating a modified example of an edging
device of the first exemplary embodiment.
Fig. 32 is a plan view illustrating a state in which a slab sandwiched between a pair
of roll members is moved in a width direction of the conveyance line to apply an incident
angle to the slab in an edging method employing the edging device illustrated in Fig.
31.
DESCRIPTION OF EMBODIMENTS
[0015] Explanation follows regarding an edging method and an edging device according to
exemplary embodiments of the present disclosure, with reference to the drawings.
First Exemplary Embodiment
[0016] Before going on to explain an edging method and an edging device of a first exemplary
embodiment, explanation is given regarding a steel strip hot rolling process, with
reference to Fig. 1.
Hot Rolling Process
[0017] As illustrated in Fig. 1, during a rough rolling procedure in a steel strip hot rolling
process, first, a slab S that has been heated to a specific temperature in a heating
furnace 10 is discharged from a discharge port 10A of the heating furnace 10, and
is placed on a conveyance line L. The conveyance line L is a path for conveying the
slab S discharged through the discharge port 10A downstream in a conveyance direction
(the direction illustrated by arrow C in Fig. 1), and is, for example, configured
by a roller conveyor, or a belt conveyor with excellent heat resistance. Note that
the conveyance line L is not limited to the above conveyors, as long as the slab S
can be conveyed.
[0018] Next, the slab S that has been discharged from the heating furnace 10 is applied
with pressure in the width direction (this is referred to as "edging" as appropriate
hereafter) by an edging device 20 of the present exemplary embodiment. The slab S
that has been subjected to edging by the edging device 20 is conveyed downstream along
the conveyance line L to a horizontal rolling mill 12.
[0019] The slab S that has been conveyed to the horizontal rolling mill 12 is applied with
pressure in the slab thickness direction (the direction illustrated by the arrow T
in Fig. 11 and Fig. 12) by horizontal rolling mill 12 (this is referred to as "thickness
rolling" as appropriate hereafter).
[0020] The thickness rolled slab S is moved repeatedly between vertical rolls 14 further
downstream on the conveyance line L than the horizontal rolling mill 12, and horizontal
rolls 16 further downstream than the vertical rolls 14, such that fine edging by the
vertical rolls 14 and thickness rolling by the horizontal rolls 16 is performed repeatedly.
In this manner, the slab S is formed into a semi-finished product, for example with
a strip thickness of approximately 40 mm, referred to as a rough bar B.
[0021] The rough bar B is then sent for a finishing rolling procedure of the hot rolling
process, in which plural horizontal rolls 18 (four in the present exemplary embodiment)
perform finishing rolling on the rough bar B, which is then taken up onto a coiler
19.
Edging Device
[0022] Next, explanation follows regarding the edging device of the present exemplary embodiment.
[0023] As illustrated in Fig. 2, the edging device 20 is a device that edges the slab S
that has been discharged from the heating furnace 10 in the rough rolling procedure.
The edging device 20 includes a pair of edging members 22, serving as an example of
a pair of edging means, a pair of plate members 24, serving as an example of a slab
incident angle changing means, temperature sensors 26, serving as an example of a
slab information acquisition means, and a controller 28, serving as an example of
a slab incident angle control means. Note that the controller 28 and the temperature
sensors 26 are omitted from illustration in Fig. 4 to Fig. 8.
[0024] The pair of edging members 22 are disposed on the conveyance line L of the slab S,
and are configured to perform edging by pressing the slab S from both sides in the
width direction of the slab S. Specifically, the edging members 22 are capable of
being moved in the width direction of the conveyance line L (this being the same direction
as the width direction of the slab S prior to edging (the direction indicated by arrow
W in Fig. 2)) by pressing mechanisms 30. The pair of edging members 22 perform edging
by repeatedly pressing the slab S from both sides in the width direction with a pressing
force from the pressing mechanisms 30. The pressing mechanisms 30 are controlled by
the controller 28, described later. Note that examples of the pressing mechanisms
30 include mechanisms employing electric motors, and mechanisms employing hydraulic
cylinders or the like.
[0025] The pair of plate members 24 are disposed upstream of the pair of edging members
22 on the conveyance line L, and are guides that extend along the conveyance line
L toward the pair of edging members 22. The plate members 24 are capable of being
moved in the width direction of the conveyance line L, and are capable of being tilted
toward a conveyance line center LC (the center in the width direction of the conveyance
line L), by moving mechanisms 32. Moreover, the pair of plate members 24 are capable
of sandwiching the slab S from both sides in the width direction with movement force
from the moving mechanisms 32 so as to adjust the position of the slab S in the width
direction of the conveyance line L, and to adjust the incident angle θ (described
in detail later) of the slab S with respect to the conveyance line center LC. The
moving mechanisms 32 are controlled by the controller 28, described later. Note that
examples of the moving mechanisms 32 include mechanisms employing electric motors,
and mechanisms employing hydraulic cylinders or the like. Plate faces 24A of the plate
members 24 on the inner side in the width direction of the conveyance line L (the
center side of the conveyance line center LC) abut lateral faces LF in the width direction
of the slab S.
[0026] Plural of the temperature sensors 26 are disposed across the width direction of the
conveyance line L between the heating furnace 10 and the edging device 20. The temperature
sensors 26 measure the temperature (surface temperature) of the slab S prior to edging.
Temperature information (a temperature distribution) measured by the plural temperature
sensors 26 is sent to the controller 28.
[0027] Based on the temperature distribution across the width direction of the slab S sent
from the plural temperature sensors 26, the controller 28 actuates the moving mechanisms
32 so as to control the positions of the pair of plate members 24 in the width direction
of the conveyance line L, and control the angles of the pair of plate members 24 with
respect to the conveyance line center LC, respectively. Specifically, according to
the temperature variation across the width direction of the slab S, the controller
28 controls the moving mechanisms 32 such that a rear end of a lateral face LFL on
the side where the temperature of the slab S is lower (referred to below as the "low
temperature side" as appropriate) is moved away from the conveyance line center LC.
The plate members 24 accordingly move in the width direction of the conveyance line
L, and tilt with respect to the conveyance line center LC so as to apply the slab
S with an incident angle θ. Note that the "incident angle θ of the slab S" referred
to here indicates an incident angle of the slab S with respect to the pair of edging
members 22 (the angle of a slab center SC with respect to the conveyance line center
LC).
[0028] The controller 28 is also sent information relating to, for example, the slab edging
method, the dimensions of the slab S, the edging amount of the slab S, and the type
of steel of the slab S, in addition to the temperature information for the slab S.
This information may be input by an operator via an external input device, or may
be acquired by some other method. The controller 28 may change the incident angle
θ based on information related to at least one of the slab edging method, the dimensions
of the slab S, the edging amount of the slab S, and the type of steel of the slab
S, in addition to the temperature information for the slab S. In other words, the
incident angle θ may be determined based on the temperature distribution and at least
one other piece of information.
[0029] Plural position sensors (for example optical sensors), not illustrated in the drawings,
are provided on the conveyance line L to detect the position of the slab S, and send
position information relating to the slab S on the conveyance line L to the controller
28.
Edging Method
[0030] Next, explanation follows regarding the edging method according to the first exemplary
embodiment. Note that the edging method of the present exemplary embodiment employs
the edging device 20.
[0031] First, the temperature of the heated slab S discharged through the discharge port
10A of the heating furnace 10 is measured by the plural temperature sensors 26, and
the measured temperature information (temperature distribution) is sent to the controller
28.
[0032] Next, as illustrated in Fig. 2, the slab S is sandwiched from both sides by the pair
of plate members 24, and the position in the width direction of the slab center SC
is aligned with the width direction position of the conveyance line center LC (known
as "centering"). Then as illustrated in Fig. 3, the pair of plate members 24 are moved
toward the outer sides in the width direction of the conveyance line L (sides going
away from the conveyance line center LC), such that the pair of plate members 24 separate
from the slab S.
[0033] Next, based on the acquired temperature information, the controller 28 controls the
moving mechanisms 32 so as to apply the incident angle θ to the slab S in cases in
which a temperature variation is present across the width direction of the slab S.
Specifically, as illustrated in Fig. 4 to Fig. 6, the slab S is again sandwiched from
both sides in the width direction s by the pair of plate members 24, and in this state,
the slab S is applied with the incident angle θ such that the rear end of the lateral
face LFL on the low temperature side of the slab S (the lateral face of the slab S
on the top side in Fig. 4 to Fig. 6) moves away from the conveyance line center LC.
Note that in the present exemplary embodiment, the incident angle θ is set according
to the temperature variation across the width direction of the slab S, and a progress
status of the edging of the slab S. Specifically, during edging of a leading end portion
of the slab S (see Fig. 4), hardly any camber occurs, and so the incident angle θ
is set to zero, or a value close to zero. As the edging progress status of the slab
S (in other words the position in the length direction of the slab S up to which edging
has been performed) progresses, the incident angle θ is made larger (see Fig. 5 and
Fig. 6). As edging of a trailing end of the slab S approaches, the incident angle
θ is reduced (see Fig. 7), and during edging of the trailing end of the slab S, the
incident angle θ is set to zero, or a value close to zero (see Fig. 8). Moreover,
the amount by which the incident angle θ is increased is set so as to become greater
the larger the temperature variation across the width direction of the slab S. Note
that the edging progress status of the slab S is computed based on position information
of the slab S from the position sensors described above.
[0034] The incident angle θ is preferably changed based on at least one piece of information
out of the edging method of the slab S, the dimensions of the slab S, the edging amount
of the slab S, or the type of steel of the slab S, in addition to the temperature
information of the slab S. Setting the incident angle θ based on such information
relating to the slab S in addition to the temperature information of the slab S enables
a more appropriate incident angle θ to be obtained for the slab S.
[0035] After the slab S has moved downstream of the pair of plate members 24 along the conveyance
line L, as illustrated in Fig. 7, the controller 28 operates the moving mechanisms
32 to return the positions in the width direction of the plate members 24 to their
original positions, and to return the tilt of the plate members 24 with respect to
the conveyance line center LC back to the original tilt. Then, as illustrated in Fig.
8, the pair of plate members 24 adopt a standby state in a state at a separation from
the conveyance line L in the width direction.
[0036] Note that in cases in which temperature variation across the width direction of the
slab S is not present (or is a permissible lower limit value), the controller 28 keeps
the pair of plate members 24 in a state separated from the slab S (the state illustrated
in Fig. 3). Accordingly, the slab S passes straight through between the plate members
24 and is subjected to edging by the pair of edging members 22.
[0037] Next, explanation follows regarding operation and advantageous effects of the first
exemplary embodiment.
[0038] First, explanation follows regarding edging methods of the slab S in Comparative
Examples 1 and 2, which are not included within the scope of the present disclosure.
Explanation will then be given regarding how the operation and advantageous effects
thereof differ from those of the present exemplary embodiment. In the following explanation,
as illustrated in Fig. 11, explanation follows regarding a case in which a temperature
variation is present across the width direction of the slab S. Note that in Fig. 11,
the vertical axis K indicates the temperature of the slab S, and the temperature difference
between both edges in the width direction of the slab S is indicated by the temperature
variation ΔK.
[0039] In Comparative Example 1, as illustrated in Fig. 9, the position in the width direction
of the slab center SC of the slab S is aligned with the position in the width direction
of the conveyance line center LC by the pair of plate members 24, after which edging
of the slab S is performed in a state in which the pair of plate members 24 have been
moved away from the slab S (in a non-restrained state). In the edging method of Comparative
Example 1, the slab S is edged by moving the pair of edging members 22 to and fro
symmetrically about the conveyance line center LC. When this is performed, both lateral
face portions LP deform to a greater extent and attain a greater slab thickness than
a central portion in the width direction of the slab S, such that the slab S is deformed
into what is referred to as a dog-bone profile. In cases in which there is no temperature
variation across the width direction of the slab S, the cross-section profile of the
slab S is symmetrical about the slab center SC, and camber does not occur. However,
if a temperature variation is present across the width direction of the slab S, out
of the two lateral face portions LP of the slab S, the lateral face portion LPH on
the side with the higher temperature (referred to below as the "high temperature side")
has lower resistance to deformation than the lateral face portion LPL on the low temperature
side, and deforms more readily. Accordingly, even if both plate members 24 move by
the same amount, the lateral face portion LPH on the high temperature side of the
slab S deforms by a greater amount in the width direction than the lateral face portion
LPL on the low temperature side. Namely, as illustrated in Fig. 11, after edging,
the slab center SC (a line bisecting the slab S along the width dimension) that, prior
to edging, was aligned with the conveyance line center LC, moves toward the lateral
face portion LPH on the high temperature side, resulting in the SCB indicated by the
double-dotted dashed lines.
[0040] When this occurs, the lateral face portion LPH on the high temperature side of the
slab S deforms more readily than the lateral face portion LPL on the low temperature
side, and so the slab thickness also increases (see the dashed lines in Fig. 11).
Accordingly, the cross-section profile of the slab S after undergoing the edging process
(see the dashed lines in Fig. 11) is not symmetrical about the slab center SC (or
the slab center SCB). Namely, thickness variation occurs between the two lateral face
portions LP of the slab S.
[0041] Moreover, the variation in deformation of the slab S is expressed as length direction
elongation of the slab S. Specifically, the length direction elongation of the slab
S is greater at the lateral face portion LPH on the high temperature side of the slab
S, and the length direction elongation of the slab S is smaller at the lateral face
portion LPL on the low temperature side of the slab S. Accordingly, the slab S bends
such that a lateral face LFH on the high temperature side becomes convex during edging.
The variation in the length direction elongation of the slab S during edging of the
slab S results in camber in the slab S after undergoing the edging process.
[0042] In this manner, in cases in which a temperature variation is present across the width
direction of the slab S, camber occurs in the slab S and slab thickness variation
occurs between the two lateral face portions LP of the slab S after undergoing the
edging process when employing the edging method of Comparative Example 1. When the
horizontal rolling mill 12 performs thickness rolling on a slab S having such slab
thickness variation across the width direction, out of the two lateral face portions
LP of the slab S, the lateral face portion LPH on the side with the thicker slab thickness
undergoes greater length direction elongation than the lateral face portion LPL on
the with the thinner slab thickness, further exacerbating the camber of the slab S.
[0043] In Comparative Example 2, corresponding to
JP-U No. S62-96943, as illustrated in Fig. 10, the slab S undergoes edging while restrained in a state
in which the position in the width direction of the slab center SC of the slab S is
aligned with the position in the width direction of the conveyance line center LC
using the pair of plate members 24. Although
JP-U No. S62-96943 makes no reference to a mechanism for reducing camber, careful investigation by the
inventors revealed the occurrence of the following phenomenon. In the edging method
of Comparative Example 2, a moment M arises in a part of the slab S subject to edging
accompanying restraint of the slab S with the position in the width direction of the
slab center SC aligned with the position in the width direction of the conveyance
line center LC. Out of the two lateral face portions LP of the slab S, the moment
M causes a compressive force FC in the length direction of the slab S to act on the
lateral face portion LPH on the high temperature side, and causes a tensile force
FT in the length direction of the slab S to act on the lateral face portion LPL on
the low temperature side. Accordingly, at the lateral face portion LP side on the
high temperature side, deformation of the slab S due to edging occurs less readily
than when unrestrained due to the compressive force acting in the length direction.
On the other hand, at the lateral face portion LPL on the low temperature side, deformation
occurs more readily than when unrestrained due to the tensile force acting in the
length direction. As a result, out of the two lateral face portions LP of the slab
S, the variation between the ease of deformation of the lateral face portion LPH on
the high temperature side and the lateral face portion LPL on the low temperature
side becomes small. Camber and slab thickness variation of the slab S are therefore
also reduced in comparison to Comparative Example 1. However, the moment M imparted
due to the restraint mentioned above is not based on information relating to the temperature
variation across the width direction of the slab S that is a cause of camber and slab
thickness variation, and so not only would camber and slab thickness variation not
be eliminated, but in some cases excessive camber and slab thickness variation could
occur.
[0044] By expanding on the investigation discussed above, the inventors arrived at the idea
that were an appropriate moment to be applied based on information relating to the
slab, both the lateral face portion LPH on the high temperature side and the lateral
face portion LPL on the low temperature side could be made to deform with a similar
degree of readiness, even if a temperature distribution were present across the width
direction of the slab S.
[0045] In the present exemplary embodiment, the slab S is applied with an incident angle
0 based on the acquired temperature information, such that that rear end of the lateral
face LFL on the low temperature side of the slab S moves away from the conveyance
line center LC. This thereby enables a more appropriate moment M to be applied than
in cases in which the position in the width direction of the slab center SC of the
slab S is restrained in alignment with the position in the width direction of the
conveyance line center LC, as in Comparative Example 2. Accordingly, out of the two
lateral face portions LP of the slab S, the compressive force FC acting on the lateral
face portion LPH on the high temperature side and the tensile force FT acting on the
lateral face portion LPL on the low temperature side can be adjusted appropriately.
This thereby enables the lateral face portion LPH on the high temperature side and
the lateral face portion LPL on the low temperature side of the slab S to deform with
a similar degree of readiness. As a result, the width direction deformation amount,
the slab thickness direction deformation amount, and the slab length direction deformation
amount of the slab S can be made similar at the lateral face portion LPH on the high
temperature side and at the lateral face portion LPL on the low temperature side,
thereby enabling camber of the slab S, and asymmetry (namely slab thickness variation)
in the cross-section profile in the width direction of the slab S, after the slab
S has been through the edging process, to be suppressed. This thereby enables camber
to be suppressed when the slab S is thickness rolled by the horizontal rolling mill
12. Note that in Fig. 12, the cross-section profile of a slab S subjected to edging
according to the present exemplary embodiment is illustrated by dashed lines, and
the cross-section profile of a slab S subjected to edging according to Comparative
Example 1 is illustrated by double-dotted dashed lines.
[0046] In particular, in the present exemplary embodiment, as illustrated in Fig. 4 to Fig.
6, the incident angle θ is changed according to the temperature variation across the
width direction of the slab S, and the edging progress status of the slab S. Specifically,
during edging of the leading end portion of the slab S, the incident angle θ is set
to zero, or a value close to zero. The incident angle θ is made larger as the edging
progress status of the slab S progresses. The incident angle θ is decreased as edging
of the trailing end of the slab S approaches, and during edging of the trailing end
portion of the slab S, the incident angle θ is changed to zero, or a value close to
zero. Accordingly, the compressive force FC acting on the lateral face portion LPH
on the high temperature side and the tensile force FT acting on the lateral face portion
LPL on the low temperature side of the slab S can be adjusted even more appropriately.
[0047] In the first exemplary embodiment, configuration is made in which the incident angle
θ is set based on the temperature distribution at the surface of the slab S; however,
the present disclosure is not limited to such a configuration. For example, configuration
may be made in which the temperature of a thickness direction central portion of the
slab S is estimated based on thermal conductivity logic, using either estimated average
temperatures of specific ranges in the width direction from the lateral faces LF of
the slab S, or the surface temperature of the slab S. The temperature variation across
the width direction of the slab S may then be computed, and the incident angle θ set
based on this temperature variation. With such configuration, properties such as the
readiness with which the slab S will deform during edging can be obtained with greater
precision than in the first exemplary embodiment, thereby enabling camber of the slab
S arising after the slab has been through the edging process, and slab thickness variation
across the width direction, to be suppressed.
[0048] Note that in the first exemplary embodiment, configuration is made in which the incident
angle θ is changed according to the edging progress status of the slab S; however,
the present disclosure is not limited to such a configuration. For example, the incident
angle θ may be fixed. This configuration may also be applied in the following exemplary
embodiments.
Second Exemplary Embodiment
[0049] Next, explanation follows regarding an edging method and an edging device of a second
exemplary embodiment. Note that configurations similar to those of the first exemplary
embodiment are allocated the same reference numerals, and explanation thereof is omitted
as appropriate.
[0050] As illustrated in Fig. 13, an edging device 40 of the present exemplary embodiment
has a similar configuration to the edging device 20 of the first exemplary embodiment,
with the exception of a configuration in which CCD cameras 42, serving as an example
of a slab information acquisition means, are provided between the heating furnace
10 and the plate members 24.
[0051] The respective CCD cameras 42 are installed at the outer sides in the width direction
of the conveyance line L, and are configured so as to image both lateral faces LF
of the slab S from the respective sides. Images captured by the CCD cameras 42 are
sent to the controller 28.
[0052] The controller 28 of the present exemplary embodiment computes a slab thickness variation
between the two lateral faces LF of the slab S based on image information from the
CCD cameras 42. Moreover, the controller 28 operates the moving mechanisms 32 to apply
the slab S with an incident angle θ, such that a lateral face LFB on the side where
the slab thickness is thicker moves away from the conveyance line center LC.
[0053] Next, explanation follows regarding the edging method of the present exemplary embodiment.
Note that the edging method of the present exemplary embodiment employs the edging
device 40.
[0054] The edging method of the present exemplary embodiment is similar to the edging method
of the first exemplary embodiment, with the exception of the configuration in which
the incident angle θ is set using the slab thickness variation between the two lateral
faces LF of the slab S, instead of the temperature variation across the width direction
of the slab S. Accordingly, the control routine of the incident angle θ of the slab
S by the controller 28 is the same as that illustrated in Fig. 4 to Fig. 6.
[0055] In the edging process of the present exemplary embodiment, based on image information
of the slab S acquired from the CCD camera 42, the controller 28 controls the moving
mechanisms 32 to apply the slab S with the incident angle θ in cases in which there
is a slab thickness variation between the two lateral faces LF of the slab S. Specifically,
the slab S is sandwiched from both sides in the width direction by the pair of plate
members 24, and in this state, the moving mechanisms 32 are controlled to move and
tilt the plate members 24 such that the rear end of the lateral face LFB (the lateral
face on the upper side in Fig. 4 to Fig. 6) on the side where the slab thickness of
the slab S is thicker moves away from the conveyance line center LC, thus applying
the slab S with the incident angle θ. Note that in the present exemplary embodiment,
the incident angle θ is set according to the slab thickness variation between the
two lateral faces LF of the slab S, and according to the edging progress status of
the slab S. Specifically, during edging of the leading end portion of the slab S (see
Fig. 4), hardly any camber deformation occurs, and so the incident angle θ is set
to zero, or a value close to zero. As the edging progress status of the slab S (in
other words, the position up to which edging has been performed along the length direction
of the slab S) progresses, the incident angle θ is made larger (see Fig. 5 and Fig.
6). As edging of the trailing end of the slab S approaches, the incident angle θ is
reduced (see Fig. 7), and during edging of the trailing end of the slab S, the incident
angle θ is set to zero, or a value close to zero (see Fig. 8). Moreover, the amount
by which the incident angle θ is increased is set so as to become greater the larger
the slab thickness variation between the two lateral faces LF of the slab S. Note
that the edging progress status of the slab S is computed based on position information
of the slab S from the position sensors mentioned above.
[0056] The incident angle θ is preferably changed based on at least one piece of information
out of the edging method of the slab S, the dimensions of the slab S, the edging amount
of the slab S, or the type of steel of the slab S, in addition to the slab thickness
variation between the two lateral faces LF of the slab S. Setting the incident angle
θ based on such information relating to the slab S in addition to the slab thickness
variation between the two lateral faces LF of the slab S enables a more appropriate
incident angle θ to be obtained for the slab S.
[0057] Next, explanation follows regarding operation and advantageous effects of the second
exemplary embodiment. Note that explanation regarding operation and advantageous effects
obtained from configurations similar to those of the first exemplary embodiment is
omitted. In the following explanation, explanation is given regarding a case in which
a slab thickness variation is present between the two lateral faces LF of the slab
S, as illustrated by imaginary lines (double-dotted dashed lines) in Fig. 17.
[0058] In cases in which edging is performed in a state in which a slab thickness variation
is present between the two lateral faces LF of the slab S, a lateral face portion
LPA including a lateral face LFA on the side where the slab thickness is thinner (the
lateral face on the left side in Fig. 17) deforms more readily than a lateral face
portion LPB including a lateral face LFB on the side where the slab thickness is thicker
(the lateral face on the right side in Fig. 17). Accordingly, deformation of the slab
S in the slab thickness direction would be expected to be greater at the lateral face
portion LPA on the side where the slab thickness is thinner than at the lateral face
portion LPB on the side where the slab thickness is thicker (see the double-dotted
dashed lines in Fig. 17). The slab thickness variation between the two lateral faces
LF of the slab S would accordingly increase after edging. If the slab S were thickness
rolled by the horizontal rolling mill 12 in this state, camber would occur to cause
the lateral face LFA on the side where the slab thickness is thicker after edging
(the side where the slab thickness is thinner prior to edging) to become convex.
[0059] By contrast, in the present exemplary embodiment, if a slab thickness variation is
present between the two lateral faces LF of the slab S, the incident angle θ of the
slab S can be set according to the slab thickness variation between the two lateral
faces LF of the slab S. This thereby enables camber and slab thickness variation across
the width direction of the slab S to be suppressed from arising after the slab S has
been through the edging process (see the dashed lines in Fig. 17). Accordingly, camber
is also suppressed when the slab S is thickness rolled by the horizontal rolling mill
12.
[0060] In the second exemplary embodiment, as illustrated in Fig. 14, the slab thickness
variation between the lateral faces on the two sides in the width direction of the
slab S is computed based on the image information captured by the CCD cameras 42;
however, the present disclosure is not limited to such a configuration. For example,
as illustrated in Fig. 15, configuration may be made in which, instead of the CCD
cameras 42, plural distance sensors 44 are installed at intervals in the width direction
above the conveyance line L, the distance to the upper face of the conveyed slab S
is measured, and the slab thickness variation across the width direction of the slab
S is computed based on the measured information. Moreover, as illustrated in Fig.
16, configuration may be made in which a moving device, not illustrated in the drawings,
is employed to move a single distance sensor 44 in the width direction of the conveyance
line L so as to measure the distance to the upper face of the slab S, and the slab
thickness variation across the width direction of the slab S is computed based on
the measured information.
Third Exemplary Embodiment
[0061] Next, explanation follows regarding an edging method and an edging device of a third
exemplary embodiment. Note that configurations similar to those of the first exemplary
embodiment are allocated the same reference numerals, and explanation thereof is omitted
as appropriate.
[0062] As illustrated in Fig. 18, an edging device 50 of the present exemplary embodiment
has a similar configuration to the edging device 20 of the first exemplary embodiment,
with the exception of a configuration in which CCD cameras 52, serving as an example
of a slab information acquisition means, are provided between the heating furnace
10 and the plate members 24.
[0063] The respective CCD cameras 52 are installed at the outer sides in the width direction
of the conveyance line L, and are configured so as to image both lateral faces LF
of the slab S from the respective sides. Images captured by the CCD cameras 52 are
sent to the controller 28.
[0064] The controller 28 of the present exemplary embodiment computes variation between
the coefficients of friction at both lateral faces LF of the slab S based on image
information from the CCD cameras 52. For example, the variation in the coefficient
of friction can be computed from differences between the states of adhered material
in the image information, or differences in the brightness distribution in the image
information. For example, of the two lateral face portions LF, the lateral face LF
on the side where there is a greater amount of adhered material (scale) has a lower
coefficient of friction with respect to the edging member 22 than the lateral face
LF on the side where there is a smaller amount of adhered material. Accordingly, the
variation between the coefficients of friction can be computed based on the difference
between the amounts of adhered material at both lateral faces LF. Moreover, for example,
out of the two lateral faces LF, the lateral face LF on the side with higher brightness
has a lower coefficient of friction than the lateral face LF on the side with lower
brightness, and so the variation between the coefficients of friction can be computed
based on the difference in brightness between the two lateral faces LF. Moreover,
the controller 28 operates the moving mechanisms 32 so as to apply the slab S with
an incident angle θ such that the lateral face LFC (the lateral face on the upper
side in Fig. 18) on the side with a higher coefficient of friction moves away from
the conveyance line center LC.
[0065] Next, explanation follows regarding the edging method of the present exemplary embodiment.
Note that the edging method of the present exemplary embodiment employs the edging
device 50.
[0066] The edging method of the present exemplary embodiment is similar to the edging method
of the first exemplary embodiment, with the exception of a configuration in which
the incident angle θ is set using the variation between the coefficients of friction
at both lateral faces LF of the slab S, instead of the temperature distribution across
the width direction of the slab S. Accordingly, the control routine for the incident
angle θ of the slab S by the controller 28 is the same as that illustrated in Fig.
4 to Fig. 6.
[0067] In the edging process of the present exemplary embodiment, based on image information
of the slab S acquired from the CCD cameras 52, the controller 28 controls the moving
mechanisms 32 to apply the slab S with the incident angle θ in cases in which a variation
is present between the coefficients of friction at both lateral faces LF of the slab
S. Specifically, the slab S is sandwiched from both sides in the width direction by
the pair of plate members 24, and in this state, the moving mechanisms 32 are controlled
to move and tilt the plate members 24 such that the rear end of the lateral face LFC
(the lateral face on the upper side in Fig. 4 to Fig. 6) on the side where the coefficient
of friction of the slab S is greater moves away from the conveyance line center LC,
thus applying the slab S with the incident angle θ. Note that in the present exemplary
embodiment, the incident angle θ is set according to the variation between the coefficients
of friction at both lateral faces LF of the slab S, and according to the edging progress
status of the slab S. Specifically, during edging of the leading end portion of the
slab S (see Fig. 4), hardly any camber deformation occurs, and so the incident angle
θ is set to zero, or a value close to zero. As the edging progress status of the slab
S (in other words, the position up to which edging has been performed along the length
direction of the slab S) progresses, the incident angle θ is made larger (see Fig.
5 and Fig. 6). As edging of the trailing end of the slab S approaches, the incident
angle θ is reduced (see Fig. 7), and during edging of the trailing end of the slab
S, the incident angle θ is set to zero, or a value close to zero (see Fig. 8). Moreover,
the amount by which the incident angle θ is increased is set so as to become greater
the larger the variation between the coefficients of friction at both lateral faces
LF of the slab S. Note that the edging progress status of the slab S is computed based
on position information of the slab S from the position sensors mentioned above.
[0068] The incident angle θ is preferably changed based on at least one piece of information
out of the edging method of the slab S, the dimensions of the slab S, the edging amount
of the slab S, or the type of steel of the slab S, in addition to the variation between
the coefficients of friction at both lateral faces LF of the slab S. Setting the incident
angle θ based on such information relating to the slab S in addition to the variation
between the coefficients of friction at both lateral faces LF of the slab S enables
a more appropriate incident angle θ to be obtained for the slab S.
[0069] Next, explanation follows regarding operation and advantageous effects of the present
exemplary embodiment. Note that explanation regarding operation and advantageous effects
obtained from configurations similar to those of the first exemplary embodiment is
omitted. In the following explanation, explanation is given regarding a case in which
a variation is present between the coefficients of friction at both lateral faces
LF of the slab S, as illustrated by imaginary lines (double-dotted dashed lines) in
Fig. 19.
[0070] In cases in which edging is performed in a state in which a variation is present
between the coefficients of friction at both lateral faces LF of the slab S, a lateral
face portion LPC including a lateral face LFC (the lateral face on the right side
in Fig. 19) on the side where the coefficient of friction is higher deforms less readily
than a lateral face portion LPD including a lateral face LFD (the lateral face on
the left side in Fig. 19) on the side where the coefficient of friction is lower.
Accordingly, as illustrated in Fig. 19, deformation of the slab S in the slab thickness
direction would be expected to be greater at the lateral face portion LPD on the side
where the coefficient of friction is lower than at the lateral face portion LPC on
the side where the coefficient of friction is higher (see the double-dotted dashed
lines in Fig. 19). The slab thickness variation between the two lateral faces LF of
the slab S after edging would accordingly increase. If the slab S were thickness rolled
by the horizontal rolling mill 12 in this state, camber would occur to cause the lateral
face LFD on the side where the slab thickness is thicker after edging (the side where
the coefficient of friction is lower) to become convex.
[0071] By contrast, in the present exemplary embodiment, even if a variation is present
between the coefficients of friction at both lateral faces LF of the slab S, the incident
angle θ of the slab S can be set according to the variation between the coefficients
of friction at both lateral faces LF of the slab S. This thereby enables camber and
slab thickness variation across the width direction of the slab S to be suppressed
from arising after the slab S has been through the edging process (see the dashed
lines in Fig. 19). Accordingly, camber is also suppressed when the slab S is thickness
rolled by the horizontal rolling mill 12.
[0072] In the third exemplary embodiment, the variation between the coefficients of friction
at both lateral faces LF of the slab S is computed based on information captured by
the CCD cameras 52; however, the present disclosure is not limited to such a configuration.
For example, configuration may be made in which the slab thickness variation between
the two lateral faces LF of the slab S is also computed from information captured
by the CCD cameras 52, and the incident angle θ of the slab S is determined based
on the slab thickness variation and the variation between the coefficients of friction.
In such cases, CCD cameras may be employed for both purposes, enabling a reduction
in the number of components configuring the device.
Fourth Exemplary Embodiment
[0073] Next, explanation follows regarding an edging method and an edging device of a fourth
exemplary embodiment. Note that configurations similar to those of the first exemplary
embodiment are allocated the same reference numerals, and explanation thereof is omitted
as appropriate.
Edging Device
[0074] As illustrated in Fig. 20, an edging device 60 of the present exemplary embodiment
has a similar configuration to the edging device 20 of the first exemplary embodiment,
with the exception of a configuration in which a CCD camera 62, serving as an example
of a slab information acquisition means, is provided at an edging output side of the
slab S, and the incident angle θ of the slab S is determined according to the camber
at the edging output side of the slab S.
[0075] The CCD camera 62 is installed over the slab S at the edging output side of the edging
device 60 (in other words, downstream of the pair of edging members 22), and is configured
so as to image the part of the slab S that has been subjected to edging, from above.
An imaging region of the CCD camera 62 is set as the region illustrated by double-dotted
dashed lines in Fig. 20 to Fig. 26. Images captured by the CCD camera 62 are sent
to the controller 28. Note that the controller 28 and the CCD camera 62 are omitted
from illustration in Fig. 21 to Fig. 26.
[0076] The controller 28 of the present exemplary embodiment computes a camber amount of
the part of the slab S that has been subjected to edging based on image information
sent from the CCD camera 62. For example, the camber amount of the part of the slab
S that has been subjected to edging can be computed from displacement in the width
direction of the conveyance line L at points on the lateral faces LF of the slab S
accompanying the progress of edging. According to the computed camber amount, the
controller 28 changes the incident angle θ of the slab S such that during edging,
out of the two lateral faces LF of the slab S, a rear end of a lateral face LFI that
is on a peripheral inside of the curve moves away from the conveyance line center
LC.
[0077] Note that in addition to the image information of the part of the slab S that has
been subjected to edging, similarly to in the first exemplary embodiment, the controller
28 is also sent information such as the slab edging method, the dimensions of the
slab S, an edging amount of the slab S, and the type of steel of the slab S. The controller
28 may determine the incident angle θ based on at least one piece of information out
of the slab edging method, the dimensions of the slab S, the edging amount of the
slab S, and the type of steel of the slab S, in addition to the image information
of the part of the slab S that has been subjected to edging.
Edging Method
[0078] Next, explanation follows regarding the edging method of the fourth exemplary embodiment.
Note that the edging method of the present exemplary embodiment employs the edging
device 60. Moreover, in the following explanation, explanation is given regarding
a case in which camber occurs at the edging output side of the slab S.
[0079] First, as illustrated in Fig. 20, a heated slab S is sandwiched from both sides by
the pair of plate members 24, and the position in the width direction of the slab
center SC is aligned with the position in the width direction of the conveyance line
center LC (what is referred to as centering). Then, as illustrated in Fig. 21, the
pair of plate members 24 are moved toward the outer sides in the width direction of
the conveyance line L (sides away from the conveyance line center LC) such that the
pair of plate members 24 separate from the slab S.
[0080] Next, as illustrated in Fig. 22, the slab S is again sandwiched in the width direction
from both sides by the pair of plate members 24, and in this state, the slab S is
applied with an incident angle 0 such that the rear end of the lateral face LFI (the
lateral face on the upper side in Fig. 23 to Fig. 25) that is on the peripheral inside
of the curve of the slab S moves away from the conveyance line center LC. Note that
until a specific amount of the leading end portion of the slab S has entered an imaging
region 62A, for example, the incident angle θ is determined based on one or plural
pieces of information out of preset information, slab S temperature information, slab
thickness variation, or the variation between the coefficients of friction, and after
the specific amount of the leading end portion of the slab S has entered the imaging
region 62A, the incident angle θ is computed based on the camber amount (described
in detail later).
[0081] Next, as illustrated in Fig. 23, after the part of the slab S that has been subjected
to edging has entered the imaging region 62A, the controller 28 computes the camber
amount of the part of the slab S that has been subjected to edging based on the image
information. The controller 28 then changes the incident angle θ of the slab S according
to the computed camber amount and the edging progress status, such that the rear end
of the lateral face LFI on the peripheral inside of the curve of the slab S during
edging moves away from the conveyance line center LC. Note that in the present exemplary
embodiment, the incident angle θ is gradually increased accompanying the progress
of edging of the slab S, as illustrated in Fig. 24.
[0082] Next, as illustrated in Fig. 25, the controller 28 decreases the incident angle θ
as edging of the trailing end of the slab S approaches. Then, during edging of the
trailing end of the slab S, the incident angle θ is set to zero, or a value close
to zero.
[0083] The incident angle θ is preferably changed based on at least one piece of information
out of the edging method of the slab S, the dimensions of the slab S, the edging amount
of the slab S, or the type of steel of the slab S, in addition to the image information
of the part of the slab S that has been subjected to edging. Setting the incident
angle 0 based on such information relating to the slab S in addition to the image
information of the part of the slab S that has been subjected to edging enables a
more appropriate incident angle θ to be obtained for the slab S.
[0084] After the slab S has moved downstream of the pair of plate members 24 along the conveyance
line L, as illustrated in Fig. 26, the controller 28 operates the moving mechanisms
32 to return the positions in the width direction of the plate members 24 to their
original positions, and to return the tilt of the plate members 24 with respect to
the conveyance line center LC to the original tilt. Then, as illustrated in Fig. 26,
the pair of plate members 24 adopt a standby state in a state at a separation from
the conveyance line L in the width direction.
[0085] Next, explanation follows regarding operation and advantageous effects of the fourth
exemplary embodiment. Note that explanation regarding operation and advantageous effects
obtained from configurations similar to those of the first exemplary embodiment is
omitted.
[0086] Camber occurs since even if the edging amount is the same on both sides of the slab
S, the readiness with which the two lateral face portions LP deform differs. Namely,
during edging of the slab S, the slab thickness increases more, and length direction
elongation is greater, at the lateral face portion LP on the side that deforms more
readily than at the lateral face portion LP on the side that deforms less readily,
and so camber and width direction slab thickness variation occur in the slab S.
[0087] In the present exemplary embodiment, the slab S is applied with an incident angle
θ according to the camber amount of the part of the slab S that has been subjected
to edging, such that the rear end of the lateral face LFI (the lateral face LF on
the upper side in Fig. 21 to Fig. 26) on the peripheral inside of the curve of the
slab S moves away from the conveyance line center LC. Accordingly, out of the two
lateral face portions LP of the slab S, the compressive force FC acting on a lateral
face portion LPO, including a lateral face LFO, on the peripheral outside of the curve
(the lateral face on the lower side in Fig. 21 to Fig. 26), and the tensile force
FT acting on a lateral face portion LPI, including a lateral face LFI, on the peripheral
inside of the curve can be adjusted more appropriately than in a configuration in
which the slab S is not applied with an incident angle θ according to the camber amount
of the part of the slab S that has been subjected to edging. This thereby enables
the ease of deformation of the lateral face portion LPO on the peripheral outside
of the curve and of the lateral face portion LPI on the peripheral inside of the curve
of the slab S to be adjusted, such that they can be made to deform with the same degree
of ease. This thereby enables camber of the slab S, and asymmetry (namely, slab thickness
variation) in the width direction cross-section profile of the slab S, after having
been through the edging process to be suppressed.
[0088] In the fourth exemplary embodiment, the incident angle θ is determined based on information
other than the camber amount at an initial stage of edging only; however, the present
disclosure is not limited to such a configuration. For example, the incident angle
θ may be determined based on both the camber amount and information other than the
camber amount of the part of the slab S that has been subjected to edging from the
initial stage through to the final stage of edging. Note that examples of information
other than the camber amount include one or plural pieces of information out of the
temperature distribution of the slab S of the first exemplary embodiment, the slab
thickness variation of the slab S of the second exemplary embodiment, and the variation
between the coefficients of friction of the slab S of the third exemplary embodiment.
In such cases, an even more appropriate incident angle θ of the slab S can be obtained.
Fifth Exemplary Embodiment
[0089] Next, explanation follows regarding an edging method and an edging device of a fifth
exemplary embodiment. Note that configurations similar to those of the fourth exemplary
embodiment are allocated the same reference numerals, and explanation thereof is omitted
as appropriate.
Edging Device
[0090] As illustrated in Fig. 27, an edging device 70 of the present exemplary embodiment
has a similar configuration to the edging device 60 of the fourth exemplary embodiment,
with the exception of a configuration in which CCD cameras 72, serving as an example
of a slab information acquisition means, are provided at an edging output side of
the slab S, and a configuration in which the incident angle θ of the slab S is determined
according to the slab thickness variation between the two lateral face portions LP
on the edging output side of the slab S.
[0091] The respective CCD cameras 72 are installed on both outer sides in the width direction
of the conveyance line L on the slab S edging output side of the edging device 70
(in other words, downstream of the pair of edging members 22), and are configured
to image both lateral face portions LP of the part of the slab S that has been subjected
to edging from the respective sides. Images captured by the CCD cameras 72 are sent
to the controller 28.
[0092] The controller 28 of the present exemplary embodiment computes a slab thickness variation
from a maximum slab thickness portions of the two lateral face portions LP at the
part of the slab S that has been subjected to edging, based on image information from
the CCD cameras 72. The controller 28 operates the moving mechanisms 32 so as to apply
the slab S with an incident angle θ, such that a rear end of a lateral face LFB on
the side where the slab thickness is thinner (the side that deforms less readily prior
to edging) out of the two lateral face portions LP of the part of the slab S that
has been subjected to edging moves away from the conveyance line center LC.
[0093] Next, explanation follows regarding the edging method of the present exemplary embodiment.
Note that the edging method of the present exemplary embodiment employs the edging
device 70.
[0094] The edging method of the present exemplary embodiment is similar to the edging method
of the fourth exemplary embodiment, with the exception of a configuration in which
the incident angle θ is set using a slab thickness variation between the two lateral
face portions LP of the slab S instead of the camber amount at the edging output side
of the slab S. Accordingly, the control routine for the incident angle θ of the slab
S by the controller 28 is the same as that illustrated in Fig. 21 to Fig. 26.
[0095] In the edging process of the present exemplary embodiment, the controller 28 computes
the slab thickness variation between the two lateral face portions LP of the part
of the slab S that has been subjected to edging based on the image information of
the slab S acquired from the CCD cameras 72. The controller 28 then changes the incident
angle θ of the slab S according to the computed slab thickness variation and the edging
progress status, such that the rear end of the lateral face LFB on the side where
the slab thickness of the slab S after edging is thinner moves away from the conveyance
line center LC. Note that in the present exemplary embodiment, the incident angle
θ is gradually increased accompanying the progress of edging of the slab S, as illustrated
in Fig. 24.
[0096] Next, as illustrated in Fig. 25, the controller 28 decreases the incident angle θ
as edging of the trailing end of the slab S approaches. Then, during edging of the
trailing end of the slab S, the incident angle θ is set to zero, or a value close
to zero.
[0097] The incident angle θ is preferably changed based on at least one piece of information
out of the edging method of the slab S, the dimensions of the slab S, the edging amount
of the slab S, or the type of steel of the slab S, in addition to the slab thickness
variation between the two lateral face portions LP of the part of the slab S that
has been subjected to edging. Setting the incident angle 0 based on such information
relating to the slab S in addition to the slab thickness variation between the two
lateral face portions LP of the part of the slab S that has been subjected to edging
enables a more appropriate incident angle θ to be obtained for the slab S.
[0098] After the slab S has moved downstream of the pair of plate members 24 along the conveyance
line L, as illustrated in Fig. 26, the controller 28 operates the moving mechanisms
32 to return the positions in the width direction of the plate members 24 to their
original positions, and to return the tilt of the plate members 24 with respect to
the conveyance line center LC to the original tilt. Then, as illustrated in Fig. 26,
the pair of plate members 24 adopt a standby state in a state at a separation from
the conveyance line L in the width direction.
[0099] Next, explanation follows regarding operation and advantageous effects of the fifth
exemplary embodiment. Note that explanation regarding operation and advantageous effects
obtained from configurations similar to those of the fourth exemplary embodiment is
omitted.
[0100] In the present exemplary embodiment, the slab S is applied with an incident angle
θ according to the slab thickness variation between the two lateral face portions
LP of the part of the slab S that has been subjected to edging, such that the rear
end of the lateral face LFB (the lateral face on the upper side in Fig. 27, and the
lateral face on the right side in Fig. 28), on the side where the slab thickness of
the slab S is thinner after edging of the slab S, moves away from the conveyance line
center LC. Accordingly, out of the two lateral face portions LP of the slab S, the
compressive force FC acting on the lateral face portion LPA, including the lateral
face LFA, on the side where the slab thickness after edging is thicker (the lateral
face on the lower side in Fig. 27, and the lateral face on the left side in Fig. 28),
and the tensile force FT acting on the lateral face portion LPB, including a lateral
face LFB, on the side where the slab thickness after edging is thinner, can be adjusted
more appropriately than in a configuration in which the slab S is not applied with
an incident angle θ according to the slab thickness variation between the two lateral
face portions LP at the part of the slab S that has been subjected to edging. This
thereby enables the ease of deformation of the lateral face portion LPA on the side
where the slab thickness is thicker, and the lateral face portion LPB on the side
where the slab thickness is thinner after edging of the slab S, to be adjusted, such
that they can be made to deform with the same degree of ease. This thereby enables
camber of the slab S and asymmetry (namely, slab thickness variation) in the width
direction cross-section profile of the slab S after having been through the edging
process to be suppressed.
[0101] As illustrated in Fig. 28, in the fifth exemplary embodiment, the slab thickness
variation between the two lateral face portions LP on the edging output side are computed
based on the image information captured by the CCD cameras 72; however, the present
disclosure is not limited to such a configuration. For example, as illustrated in
Fig. 29, configuration may be made in which, instead of the CCD cameras 72, plural
distance sensors 74 are installed above the conveyance line L at intervals in the
width direction, the distance to the upper face of the conveyed slab S is measured,
and the slab thickness variation across the width direction of the slab S is computed
based on the measured information. Moreover, as illustrated in Fig. 30, configuration
may be made in which a moving device, not illustrated in the drawings, is employed
to move a single distance sensor 74 in the width direction of the conveyance line
L so as to measure the distance to the upper face of the slab S, and the slab thickness
variation across the width direction of the slab S on the edging output side is computed
based on the measured information.
[0102] In the first to the fifth exemplary embodiments, configuration is made in which the
plate members 24 are employed to apply the slab S with the incident angle θ; however,
the present disclosure is not limited to such a configuration. For example, configuration
may be made in which, as in the edging device 80 illustrated in Fig. 31 and Fig. 32,
a pair of roll members 84 are positioned on either side of the slab S, and the pair
of roll members 84, capable of rotating about an axial direction running in the slab
thickness direction, are employed to apply the slab S with the incident angle θ. The
roll members 84 are capable of being moved in the width direction of the conveyance
line L by moving mechanisms 82 that are controlled by the controller 28. When such
rotatable roll members 84 are employed, the moving mechanisms 82 are not required
to tilt the roll members 84 with respect to the conveyance line L, thereby simplifying
the configuration. Moreover, friction between the roll members 84 and the slab S is
suppressed since the roll members 84 can be turned by drag of the slab S that is being
conveyed.
[0103] In the first to the fifth exemplary embodiments, configuration is made in which the
pressing mechanisms 30 that move the pair of edging members 22 in the width direction
are controlled by the controller 28; however, the present disclosure is not limited
to such a configuration. For example, configuration may be made in which the pressing
mechanisms 30 are controlled by another controller separate to the controller 28.
[0104] Explanation has been given regarding several exemplary embodiments of the present
disclosure; however, the present disclosure is not limited to the above, and obviously
various other modifications may be made within a range not departing from the spirit
of the present disclosure. For example, the configurations of the first to the fifth
exemplary embodiments may be combined as desired. Namely, the incident angle θ of
the slab S may be determined using a combination of any two or more pieces of information
out of the temperature distribution of the slab S prior to edging, the slab thickness
variation, the variation between coefficients of friction, the camber amount of the
part that has been subjected to edging, the slab thickness variation of the part that
has been subjected to edging, or other information.
[0105] The exemplary embodiment described above further discloses the following items.
Item 1
[0106] An edging method including changing an incident angle of a slab with respect to a
pair of edging means that are disposed on a conveyance line of the slab and that edge
the slab based on information relating to the slab acquired at at least one of prior
to edging or after edging.
Item 2
[0107] The edging method of item 1, wherein: the information includes a temperature distribution
across a width direction of the slab prior to edging; and the incident angle of the
slab is changed according to the temperature distribution.
Item 3
[0108] The edging method of item 1, wherein: the information includes a camber of the slab
after edging; and the incident angle of the slab is changed according to the camber
of the slab.
Item 4
[0109] The edging method of item 1, wherein: the information includes a slab thickness variation
across a width direction of the slab at at least one of prior to edging or after edging;
and the incident angle of the slab is changed according to the slab thickness variation.
Item 5
[0110] The edging method of item 1, wherein: the information includes a variation between
coefficients of friction of both lateral faces in a width direction of the slab with
respect to the edging means prior to edging; and the incident angle of the slab is
changed according to the variation between the coefficients of friction.
Item 6
[0111] The edging method of any one of items 2 to 5, wherein the incident angle of the slab
is also changed based on, in addition to the information, at least one of a dimension
of the slab, an edging amount of the slab, or a type of steel of the slab.
Item 7
[0112] The edging method of any one of items 1 to 6, wherein the incident angle is changed
by contacting a moving member capable of moving in a width direction of the slab against
a lateral face in the width direction of the slab further upstream than the pair of
edging means on the conveyance line.
Item 8
[0113] An edging device including: a pair of edging means that are disposed on a conveyance
line of a slab, and that perform edging by pressing the slab from both sides in the
width direction of the slab; a slab incident angle changing means that is disposed
further upstream than the pair of edging means on the conveyance line, and that changes
an incident angle of the slab; a slab information acquisition means that acquires
information relating to the slab at at least one of prior to edging or after edging;
and a slab incident angle control means that controls the slab incident angle changing
means based on information relating to the slab acquired by the slab information acquisition
means.
Item 9
[0114] The edging device of item 8, wherein: the slab information acquisition means includes
a means to acquire a temperature distribution across the width direction of the slab
prior to edging; and the slab incident angle control means controls the slab incident
angle changing means according to the temperature distribution.
Item 10
[0115] The edging device of item 8, wherein: the slab information acquisition means includes
means to acquire a camber amount of the slab after edging; and the slab incident angle
control means controls the slab incident angle changing means according to the camber
amount of the slab.
Item 11
[0116] The edging device of item 8, wherein: the slab information acquisition means includes
means to acquire a slab thickness variation across a width direction of the slab at
at least one of prior to edging or after edging; and the slab incident angle control
means controls the slab incident angle changing means according to a size of the slab
thickness variation.
Item 12
[0117] The edging device of item 8, wherein: the slab information acquisition means includes
means to acquire a variation between coefficients of friction of both lateral faces
in a width direction of the slab with respect to the edging means prior to edging;
and the slab incident angle control means controls the slab incident angle changing
means according to the variation between the coefficients of friction.
Item 13
[0118] The edging device of any one of items 8 to 12, wherein the slab incident angle changing
means includes: a pair of roll members that are positioned on both sides of the slab
and that are capable of rotating about an axial direction running in a slab thickness
direction of the slab; and a moving means that moves the roll members in a width direction
of the slab.
Item 14
[0119] The edging device of any one of items 8 to 12, wherein the slab incident angle changing
means includes: plate members extending toward the pair of edging means and including
plate faces that contact lateral faces in the width direction of the slab; and a moving
means that moves the plate members in a width direction of the slab.